Abstract: In this study, we utilized Parallel Monte-Carlo Ray-tracing model to quantify the effect of sky radiation and leaf scattering on canopy light interception. The simulation showed that more light intercepted by canopy and more leaves irradiated by sky light in diffuse radiation than in direct radiation with equal total radiant flux. When solar elevation is lower than 60°, canopy got more irradiance in clear sky than in overcast, while there was at least 60% of leaves got more irradiance in overcast than in clear sky. It was also manifested that the influence of leaf scattering on canopy light distribution was related with the wavelength of light. We simulated the light distribution in red (650 nm), green (540 nm) and infrared (760 nm) and found that the influence of leaf scattering on canopy light interception was largest in infrared, smaller in red, the smallest in green. These results can provide basic references for the research of plant canopy photosynthetic productivity and light environment simulation.